The supplementary motor area syndrome: a neurosurgical review.

The supplementary motor area (SMA) syndrome is a frequently encountered clinical phenomenon associated with surgery of the dorsomedial prefrontal lobe. The region has a known motor sequencing function and the dominant pre-SMA specifically is associated with more complex language functions; the SMA is furthermore incorporated in the negative motor network. The SMA has a rich interconnectivity with other cortical regions and subcortical structures using the frontal aslant tract (FAT) and the frontostriatal tract (FST). The development of the SMA syndrome is positively correlated with the extent of resection of the SMA region, especially its medial side. This may be due to interruption of the nearby callosal association fibres as the contralateral SMA has a particular important function in brain plasticity after SMA surgery. The syndrome is characterized by a profound decrease in interhemispheric connectivity of the motor network hubs. Clinical improvement is related to increasing connectivity between the contralateral SMA region and the ipsilateral motor hubs. Overall, most patients know a full recovery of the SMA syndrome, however a minority of patients might continue to suffer from mild motor and speech dysfunction. Rarely, no recovery of neurological function after SMA region resection is reported.

Survival impact of incidental subventricular zone irradiation in IDH-wildtype glioblastoma.

BACKGROUND AND PURPOSE: The subventricular zone (SVZ) is an important niche for neural stem cells but probably also for brain tumor propagating cells, including the glioblastoma stem cell. The SVZ may become a target for radiation therapy in glioblastoma patients. However, reports studying the effect of irradiation of the SVZ on glioblastoma patient survival show conflicting results. We studied the correlation between incidental SVZ radiation dose and survival in a cohort of isocitrate dehydrogenase-wildtype (IDHwt) glioblastoma patients with inclusion of important survival prognosticators. PATIENTS AND METHODS: In this retrospective analysis, only adult patients with supratentorial IDHwt glioblastoma were included who were treated with temozolomide-based chemoradiotherapy after surgery. The SVZ was contoured on the radiotherapy planning imaging. Cox proportional regression overall survival (OS) analysis was used to study the correlation between SVZ dose and survival. Age, Karnofsky Performance Score, extent of resection and O6-methylguanine-methyl-DNA-transferase gene promoter (MGMTp) methylation were used as covariates in multivariate analysis. RESULTS: In total, 137 patients were included. Median OS was 13.3 months. The MGMTp methylation was present in 40% of cases. Ipsilateral SVZ (iSVZ) mean dose was 44.4 Gy and 27.2 Gy for the contralateral SVZ (cSVZ). Univariate survival analysis showed an inverse relationship between cSVZ mean dose and OS (HR 1.029 (1.003-1.057); p= .032). However, there was no correlation between cSVZ mean dose and OS in multivariate analysis. iSVZ dose did not correlate with survival. CONCLUSION: In this cohort of 137 IDHwt glioblastoma patients, iSVZ did not correlate with OS. Higher cSVZ dose was inversely correlated with OS in univariate survival analysis but lost its significance in multivariate analysis, including MGMTp-methylation. Hence, the correlation between SVZ radiation and glioblastoma patient survival remains unclear. Carefully designed prospective studies are needed to provide unequivocal results on this controversial topic.

Hydroxyapatite cranioplasty: a retrospective evaluation of osteointegration in 17 cases.

BACKGROUND: Cranial reconstruction with autologous bone is still the gold standard although several biomaterials are available to re-establish the integrity of the cranial vault. Due to their biological and morphological characteristics, hydroxyapatite implants show promising results in small clinical cohort studies, especially within the paediatric population. Its biocompatibility and osteoconductivity should allow the formation of osseous bridging at the skull-prosthesis interface. OBJECTIVE: To examine the possible occurrence of osteointegration and to quantify it. METHODS: A retrospective study of patients with a hydroxyapatite implant from 2010 to 2014 at our neurosurgical department was conducted. Demographic, surgical and radiological data were studied. A senior neuroradiologist, a staff member neurosurgeon and a resident neurosurgeon independently performed the radiological evaluation. A new software analysis technique was developed to objectively quantify the degree of osteointegration. RESULTS: Seventeen implants were evaluated with an average patient age of 39 years and a mean follow-up of 155 weeks. Through radiologic evaluation, osseous bridging was deemed higher than 50% in six prostheses and higher than 75% in three. In five patients, no osteointegration could be seen. The remaining patients exhibited sparse signs of osteointegration, estimated between 10 and 50%. Software analysis showed an average osteointegration ratio of 37.4% with a 400-HU filter and 27.3% with a 700-HU filter. CONCLUSION: In this small retrospective study of cranial hydroxyapatite implants, osteointegration did occur and to a degree of more than 50% in 1/3 of the patients.

Comparison of hybrid constructs with 2-level artificial disc replacement and 2-level anterior cervical discectomy and fusion for surgical reconstruction of the cervical spine: a kinematic study in whole cadavers.

BACKGROUND: Multi-level cervical degeneration of the spine is a common clinical pathology that is often repaired by anterior cervical discectomy and fusion (ACDF). The aim of this study was to investigate the kinematics of the cervical spine after hybrid surgery compared with 2-level ACDF. MATERIAL AND METHODS: Five freshly frozen, unembalmed whole human cadavers were used including 3 males and 2 females with a mean age of 51 ± 8 years. After evaluating the intact spine for range of motion (ROM), sagittal alignment and instantaneous center of rotation (ICR), each cadaver underwent 4 consecutive surgeries: 2-level artificial disc replacement (ADR) from C4 to C6 (ADR surgery); 2-level ACDF from C4 to C6 (ACDF surgery); hybrid C4-5 ACDF and C5-6 ADR (ACDF+ADR surgery); and hybrid C4-5 ADR and C5-6 ACDF (ADR+ACDF surgery). The ROM and ICR of adjacent intact segments (C3-4; C6-7), and whole sagittal alignment were revaluated. RESULTS: Two-level ACDF resulted in increased ROM at C3-4 and C6-7 compared with intact spine. ROM was significantly different to intact spine using ACDF surgery at C3-C4 and C6-C7 and ROM was increased with ACDF+ADR surgery at C6-C7 (all P<0.05). No improvement in sagittal alignment was observed with any approach. The localization of the ICR shifted upwards and anteriorly at C3-C4 after reconstruction. ICR changes at C3-C4 were greatest for ADR+ACDF surgery and were significantly different to ACDF surgery (P<0.05), but not between ADR surgery and ACDF+ADR surgery. At C6-C7, the ICR was more posterior and superior than in the intact condition. The greatest change in ICR was observed in ACDF surgery at the C6-C7 level, significantly different from the other groups (P<0.05). CONCLUSIONS: For 2-level reconstruction, hybrid surgery and ADR did not alter ROM and minimally changed ICR at the adjacent-level. The type of surgery had a significant impact on the ICR location. This suggests that hybrid surgery may be a viable option for 2-level cervical surgery.

Partial resection offers an overall survival benefit over biopsy in MGMT-unmethylated IDH-wildtype glioblastoma patients.

Background Isocitrate dehydrogenase (IDH)-wildtype glioblastoma patients with O6-methylguanine-DNA-methyltransferase (MGMT)-unmethylated tumors have the worst outcome of all glioblastoma patients. The overall survival (OS) benefit of partial resection of glioblastoma compared to biopsy only remains controversial specifically in relation to molecular factors. In this report, we analyzed the effect of incomplete resection on OS compared to biopsy only in a cohort of IDH-wildtype glioblastoma patients who were uniformly treated with temozolomide-based chemoradiotherapy (TMZ-CR) after surgery. Material & Methods A retrospective study was conducted including only glioblastoma patients who were treated with TMZ-CR after surgery from two centers. Surgical groups were defined as biopsy only, partial resection (PR) or gross total resection depending on the presence of contrast-enhancing tumor on postoperative imaging. IDH-mutation was determined using next generation sequencing technique and MGMT-methylation was analyzed with semi-quantitative methylation-specific polymerase chain reaction. Next to descriptive statistics, univariate and multivariate survival analyses were performed using Kaplan-Meier estimates and Cox regression models. Results In total, 159 patients were included. 37 patients underwent biopsy only and 73 partial resections. 99 patients (62.3%) harbored unmethylated tumors. Median OS for the whole patient group was 13.4 months. In the subgroup of patients with unmethylated tumors, PR yielded a median OS of 12.2 months vs 7.6 months for biopsy patients (P = 0.003). PR proved an independent beneficial prognostic factor in multivariate Cox regression model, together with age, Karnofsky Performance Score and MGMT-methylation. Conclusion In IDH-wildtype glioblastoma patients with MGMT-unmethylated tumors, treated with chemoradiotherapy after surgery, PR yields a significant OS benefit compared to biopsy.

Migration of pump for intrathecal drug delivery into the peritoneal cavity. Case report.

BACKGROUND: We report on a patient in whom a subfascially implanted pump for the intrathecal delivery of baclofen spontaneously migrated into the peritoneal cavity. CASE DESCRIPTION: A 54-year-old male patient presented with a refilling problem of a drug pump that had been implanted 16 months earlier subfascially through a right-sided incision 10 cm below the costal margin. Because we were unable to refill the pump even under fluoroscopy, we presumed a backward turning of the pump. At exploration, we found that the deeper part of the pocket had spontaneously eroded and had caused the migration of the pump into the peritoneal cavity. The peritoneum and the abdominal wall were closed and the pump was placed in a subcutaneous pouch. We suppose that the migration of the pump was due to its particular implantation site with the lower extent of the device at or below the level of the linea semilunaris. Below this line, the aponeuroses of all 3 lateral abdominal muscles pass in front of the rectus muscle, leaving only the transversal fascia underneath the rectus, which is not a solid layer. Not considering this anatomical detail may facilitate the inward migration of implanted material. CONCLUSION: When creating a pocket for subfascial implantation, a high subcostal incision should be used so that the lower extent of the pocket will still be above the level of the linea semilunaris, hence ensuring a strong fascial layer between the pump and the peritoneum.

Complete Resection of an Intradural Extramedullary Foramen Magnum Cavernous Malformation.

Only few case reports of intradural extramedullary-located cavernous angiomas are available. This report describes an extra-axial hemorrhagic lesion located on the lateral surface of the medulla oblongata at the foramen magnum. Follow-up magnetic resonance imaing clearly demonstrated growth of the lesion, probably due to repetitive intralesional hemorrhaging. Initially, a right vertebral artery aneurysm or an arteriovenous malformation was suspected. Digital subtraction angiography excluded these differential diagnoses, although doubt remained concerning the possibility of a thrombosed aneurysm. Preoperatively, the lesion did not had the typical macroscopical aspect of a cavernoma and appeared rather as an expansive encapsulated multicystic vascular lesion. Nevertheless, pathologic analysis confirmed the diagnosis of a cavernous hemangioma. Complete microsurgical resection was obtained without neurologic impairment.

Technical feasibility of [18F]FET and [18F]FAZA PET guided radiotherapy in a F98 glioblastoma rat model.

BACKGROUND: Glioblastoma (GB) is the most common primary malignant brain tumor. Standard medical treatment consists of a maximal safe surgical resection, subsequently radiation therapy (RT) and chemotherapy with temozolomide (TMZ). An accurate definition of the tumor volume is of utmost importance for guiding RT. In this project we investigated the feasibility and treatment response of subvolume boosting to a PET-defined tumor part. METHOD: F98 GB cells inoculated in the rat brain were imaged using T2- and contrast-enhanced T1-weighted (T1w) MRI. A dose of 20 Gy (5 × 5 mm2) was delivered to the target volume delineated based on T1w MRI for three treatment groups. Two of those treatment groups received an additional radiation boost of 5 Gy (1 × 1 mm2) delivered to the region either with maximum [18F]FET or [18F]FAZA PET tracer uptake, respectively. All therapy groups received intraperitoneal (IP) injections of TMZ. Finally, a control group received no RT and only control IP injections. The average, minimum and maximum dose, as well as the D90-, D50- and D2- values were calculated for nine rats using both RT plans. To evaluate response to therapy, follow-up tumor volumes were delineated based on T1w MRI. RESULTS: When comparing the dose volume histograms, a significant difference was found exclusively between the D2-values. A significant difference in tumor growth was only found between active therapy and sham therapy respectively, while no significant differences were found when comparing the three treatment groups. CONCLUSION: In this study we showed the feasibility of PET guided subvolume boosting of F98 glioblastoma in rats. No evidence was found for a beneficial effect regarding tumor response. However, improvements for dose targeting in rodents and studies investigating new targeted drugs for GB treatment are mandatory.

Treating Hydrocephalus with Retrograde Ventriculosinus Shunt: Prospective Clinical Study.

BACKGROUND: Since the 1950s, hydrocephalus has been be treated with cerebrospinal fluid (CSF) shunts, usually to the peritoneal cavity or to the right cardiac atrium. However, because of their siphoning effect, these shunts lead to nonphysiologic CSF drainage, with possible comorbidity and high revision rates. More sophisticated shunt valve systems significantly increase costs and technical complexity and remain unsuccessful in a subgroup of patients. In an attempt to obtain physiologic CSF shunting, many neurosurgical pioneers shunted towards the dural sinuses, taking advantage of the physiologic antisiphoning effect of the internal jugular veins. Despite several promising reports, the ventriculosinus shunts have not yet become standard neurosurgical practice. METHODS: In this single-center prospective clinical study, we implanted the retrograde ventriculosinus shunt, as advocated by El-Shafei, in 10 patients. This article reports on our operation technique and long-term outcome, including 4 patients in whom this shunt was implanted as a rescue operation. RESULTS: Implantation of a ventriculosinus shunt proved to be feasible, warranting physiologic drainage of CSF. However, in only 3 of 14 patients, functionality of the retrograde ventriculosinus shunt was maintained during more than 6 years of follow-up. In our opinion, these shunts fail because present venous access devices are difficult to implant correctly and become too easily obstructed. After discussion of possible causes of this frequent obstruction, a new dural venous sinus access device is presented. CONCLUSION: An easy-to-implant and thrombogenic-resistant dural venous sinus access device needs to be developed before ventriculosinus shunting can become general practice.

Outcome of Anterior Lumbar Interbody Fusion: A Retrospective Study of Clinical and Radiologic Parameters.

OBJECTIVE: This study critically evaluates the long-term results of standalone anterior lumbar interbody fusion (ALIF), without use of rhBMP-2, as a therapeutic option for symptomatic patients with degenerative disc disease (DDD). Furthermore, this study intends to identify predictive parameters for anterior lumbar interbody fusion outcome. METHODS: A retrospective cohort study with additional telephone interview to obtain missing data was performed. All patients who underwent an L4-L5 or L5-S1 ALIF-procedure, or both, in the period between 2006 and 2011 were identified. The medical files of 123 patients with 154 fusion levels were reviewed. All patients were contacted by telephone to gather supplementary and missing information. Pain and functionality scores (Visual Analogue Scale [VAS] and Oswestry Disability Index [ODI]), radiologic (intervertebral disc height, Modic and Pfirrmann classifications), and different clinical parameters were gathered. RESULTS: The mean age of the population at surgery was 46.2 years. Overall, 59 female and 64 male patients were included in the study. The mean VAS score for back and leg pain improved significantly (P < 0.001) with 5 and 4.4 points respectively at 3-year follow-up. Modic-type I changes are associated with a better improvement in VAS score for back pain (P = 0.026), Pfirrmann-grades IV and V and an intervertebral disc height of less than 5 mm are associated with a better improvement in leg pain (respective P-values: 0.045 and 0.033). Overall, 89% of patients would reconsider the surgical intervention. CONCLUSIONS: The ALIF technique is a durable treatment option for patients with DDD. This study suggests different predictive parameters for treatment outcome.

Correction: Kinetic Modeling and Graphical Analysis of 18F-Fluoromethylcholine (FCho), 18F-Fluoroethyltyrosine (FET) and 18F-Fluorodeoxyglucose (FDG) PET for the Fiscrimination between High-Grade Glioma and Radiation Necrosis in Rats.

[This corrects the article DOI: 10.1371/journal.pone.0161845.].

Kinetic Modeling and Graphical Analysis of 18F-Fluoromethylcholine (FCho), 18F-Fluoroethyltyrosine (FET) and 18F-Fluorodeoxyglucose (FDG) PET for the Fiscrimination between High-Grade Glioma and Radiation Necrosis in Rats.

BACKGROUND: Discrimination between glioblastoma (GB) and radiation necrosis (RN) post-irradiation remains challenging but has a large impact on further treatment and prognosis. In this study, the uptake mechanisms of 18F-fluorodeoxyglucose (18F-FDG), 18F-fluoroethyltyrosine (18F-FET) and 18F-fluoromethylcholine (18F-FCho) positron emission tomography (PET) tracers were investigated in a F98 GB and RN rat model applying kinetic modeling (KM) and graphical analysis (GA) to clarify our previous results. METHODS: Dynamic 18F-FDG (GB n = 6 and RN n = 5), 18F-FET (GB n = 5 and RN n = 5) and 18F-FCho PET (GB n = 5 and RN n = 5) were acquired with continuous arterial blood sampling. Arterial input function (AIF) corrections, KM and GA were performed. RESULTS: The influx rate (Ki) of 18F-FDG uptake described by a 2-compartmental model (CM) or using Patlak GA, showed more trapping (k3) in GB (0.07 min-1) compared to RN (0.04 min-1) (p = 0.017). K1 of 18F-FET was significantly higher in GB (0.06 ml/ccm/min) compared to RN (0.02 ml/ccm/min), quantified using a 1-CM and Logan GA (p = 0.036). 18F-FCho was rapidly oxidized complicating data interpretation. Using a 1-CM and Logan GA no clear differences were found to discriminate GB from RN. CONCLUSIONS: Based on our results we concluded that using KM and GA both 18F-FDG and 18F-FET were able to discriminate GB from RN. Using a 2-CM model more trapping of 18F-FDG was found in GB compared to RN. Secondly, the influx of 18F-FET was higher in GB compared to RN using a 1-CM model. Important correlations were found between SUV and kinetic or graphical measures for 18F-FDG and 18F-FET. 18F-FCho PET did not allow discrimination between GB and RN.

(18)F-fluoromethylcholine (FCho), (18)F-fluoroethyltyrosine (FET), and (18)F-fluorodeoxyglucose (FDG) for the discrimination between high-grade glioma and radiation necrosis in rats: a PET study.

INTRODUCTION: Discrimination between (high-grade) brain tumor recurrence and radiation necrosis (RN) remains a diagnostic challenge because both entities have similar imaging characteristics on conventional magnetic resonance imaging (MRI). Metabolic imaging, such as positron emission tomography (PET) could overcome this diagnostic dilemma. In this study, we investigated the potential of 2-[(18)F]-fluoro-2-deoxy-D-glucose ((18)F-FDG), O-(2-[(18)F]-fluoroethyl)-L-tyrosine ((18)F-FET), and [(18)F]-Fluoromethyl-dimethyl-2-hydroxyethylammonium ((18)F-fluoromethylcholine, (18)F-FCho) PET in discriminating high-grade tumor from RN. METHODS: We developed a glioblastoma (GB) rat model by inoculating F98 GB cells into the right frontal region. Induction of RN was achieved by irradiating the right frontal region with 60 Gy using three arcs with a beam aperture of 3×3 mm (n=3). Dynamic PET imaging with (18)F-FDG, (18)F-FET, and (18)F-FCho, as well as (18)F-FDG PET at a delayed time interval (240 min postinjection), was acquired. RESULTS: MRI revealed contrast-enhancing tumors at 15 days after inoculation (n=4) and contrast-enhancing RN lesions 5-6 months postirradiation (n=3). On (18)F-FDG PET, the mean lesion-to-normal ratio (LNRmean) was significantly higher in GB than in RN (p=0.034). The difference in the LNRmean between tumors and RN was higher on the late (18)F-FDG PET images than on the PET images reconstructed from the last time frame of the dynamic acquisition (this is at a conventional time interval). LNRs obtained from (18)F-FCho PET were not significantly different between GB and RN (p=1.000). On (18)F-FET PET, the LNRmean was significantly higher in GB compared to RN (p=0.034). CONCLUSIONS: Unlike (18)F-FCho, (18)F-FDG and (18)F-FET PET were effective in discriminating GB from RN. Interestingly, in the case of (18)F-FDG, delayed PET seems particularly useful. ADVANCES IN KNOWLEDGE AND IMPLICATIONS FOR PATIENT CARE: Our results suggest that (delayed) (18)F-FDG and (18)F-FET PET can be used to discriminate GB (recurrence) from RN. Confirmation of these results in clinical studies is needed.

Can recurrence of meningiomas be predicted?

After resection of meningiomas the clinical evolution remains problematic, as no clear-cut predictive criteria are available. In vitro evaluation of meningiomas might help to predict their evolution in vivo after resection. For this goal a confrontation model was tested. A group of 105 patients operated for meningiomas between 1986 and 1997 were reviewed at 3, 5, 10 and 15 years for tumour evolution by tomodensitometry or magnetic resonance. At operation a fragment of these resected tumours was explanted for cell culture and was confronted with embryonic chick heart as a host tissue. The confrontation between tumour- derived cells and host tissue resulted in three different patterns: respectively a regressive, a non-invasive and an invasive pattern. Resection type, proliferation markers (Ki67 and PCNA) and in vitro confrontation patterns were significant (p<0.05) factors in predicting the postsurgical evolution of meningiomas. No correlation was found between proliferation markers and the behaviour in vitro, but invasion in vitro was strictly correlated with recurrence and malignancy of meningiomas.

Primary resected meningiomas: relapses and proliferation markers.

UNLABELLED: Relapses of meningiomas are a well known phenomenon during follow-up. The significance of sex, age, surgical treatment and mitotic frequency with regard to relapses are still a matter of debate. PATIENTS AND METHODS: The study included 125 meningioma patients who underwent surgical intervention between 1986 and 1997 They were in follow-up for 3, 5, 10 and 15 years; they were grouped as "stable" or "relapsing" tumours. The follow-up was based on magnetic resonance image (MRI) and tomodensitometry (TDM). The labelling index for Ki67 and PCNA (proliferation markers) was scored at resection. Risk factors for relapse were reviewed using univariate analysis and Cox hazards model. RESULTS: One hundred and twenty-five patients were under medical control of whom 26 showed a relapse. Among them 25 arose from subtotal resected tumours and 1 was a recurrence. Relapses comprised 16 females and 10 males. Tumour relapses at 3,5,10 and 15 years were, respectively, 8.8%, 13.6%, 17.6% and 20.8%. Proliferation markers, at group level, were statistically significantly different to distinguish stable from relapsing and malignant from benign meningiomas. Factors significantly associated with tumour relapse in univariate analysis were incomplete resection, histopathology and proliferation markers. In multivariate analysis the proliferation markers and incomplete resection were the only significant risk factors (p<0.05) for relapse. CONCLUSION: To avoid relapses of meningiomas, total resection is recommended. The resection type and proliferation markers are predictive factors for tumour relapse. The proliferation markers cannot be applied at the individual level.

To investigate the effect of osteoporosis and intervertebral disc degeneration on the endplate cartilage injury in rats.

OBJECTIVES: To investigate the effect of osteoporosis and intervertebral disc degeneration on the endplate cartilage injury in rats. METHODS: A total of 48 female Sprague Dawley rats (3 months) were randomly divided into Groups A, B, C and D with 12 rats in each group. Osteoporosis and intervertebral disc degeneration composite model, simple degeneration model and simple osteoporosis model were prepared in Groups A, B and C respectively. After modeling, four rats of each group at 12th, 18th and 24th week were sacrificed. Intervertebral height of cervical vertebra C6/C7 was measured. Micro-CT was used to image the endplate of cephalic and caudal cartilage at C6/C7 intervertebral disc. Abraded area rate of C6 caudal and C7 cephalic cartilage endplate was calculated, and then C6/C7 intervertebral disc was routinely embedded and sectioned, stained with safranin O to observe histological changes microscopically. RESULTS: At 12, 18 and 24 weeks, intervertebral disc height of C6/C7 were (0.58±0.09) mm, (0.53±0.04) mm and (0.04±0.06) mm in Group A rats, (0.55±0.05) mm, (0.52±0.07) mm and (0.07±0.05) mm in Group B rats. At 24th week, intervertebral disc height of Group A rats was significantly lower than that of Group B rats (P<0.05); intervertebral disc height of Groups A and B rats at each time point were significantly lower than that of Groups C and D (P<0.05). There was no significantly statistical difference of intervertebral disc height between Groups C and D (P>0.05). At 12 and 18 weeks, the abraded rate of C6 caudal and C7 cephalic cartilage endplate in Group A rats were significantly higher than that in Groups B, C and D rats (P<0.05); the abraded rate in Group B was significantly higher than that in Groups C and D (P>0.05). Microscopic observation of CT showed that ventral defects in C6 caudal or C7 cephalic cartilage endplate in Groups A and B appeared after 12 weeks of modeling; obvious cracks were found in front of the C6 and C7 vertebral body, and cartilage defect shown the trend of "repairing" at 18 and 24 weeks after modeling. CONCLUSIONS: Intervertebral disc degeneration and osteoporosis can cause damage to the cartilage endplate. Co-existence of these two factors can induce more serious damage to the endplate, which has possitive correlation with intervertebral disc degeneration. Osteoporosis plays a certain role in intervertebral disc degeneration process, and accelerates the degeneration of intervertebral disc in a specific time window.

Validation of 18F-FDG PET at conventional and delayed intervals for the discrimination of high-grade from low-grade gliomas: a stereotactic PET and MRI study.

AIM: The aim of this study was to validate 18F-FDG PET imaging for differentiating high-grade gliomas (HGGs) from low-grade gliomas (LGGs). METHODS: Twenty-one patients with gliomas undergoing a stereotactic biopsy underwent PET scanning at conventional and delayed intervals, diagnostic and stereotactic MR examinations. To calculate the uptake at the biopsy site, a 2-mm voxel was selected. Uptake in this voxel was expressed as a percentage of the average uptake per voxel in the normal brain. The difference in uptake between HGG and LGG at conventional and late intervals and the difference in uptake difference between HGG and LGG at both intervals were analyzed using t tests as well as a mixed-model analysis of variance. RESULTS: At conventional intervals, uptake in LGG was 67% of that in the normal brain. Between early and late intervals, a significant decrease in uptake of 11% (±2.5%) was noted (P = 0.001). Uptake in HGG at conventional intervals was 138% of that in the normal brain. Between early and late intervals, a significant increase in uptake of 43% (±11%) was noted (P = 0.005). The difference in uptake between HGG and LGG was significant both at conventional and delayed intervals (P < 0.001). Moreover, the difference in uptake between both groups was significantly greater (31%) at delayed than at conventional intervals (2%) (P < 0.001). CONCLUSIONS: The results of this correlative study between tumor grade and 18F-FDG uptake both determined at the stereotactic biopsy site indicate that PET, particularly at delayed intervals, is valid for discriminating LGG from HGG.

Distribution patterns of 18F-labelled fluoromethylcholine in normal structures and tumors of the head: a PET/MRI evaluation.

PURPOSE: To evaluate the distribution of 18F-labelled fluoromethylcholine (FCho) in normal structures and tumors of the head region using positron emission tomography (PET) and magnetic resonance imaging. MATERIALS AND METHODS: We retrospectively reviewed the positron emission tomography, magnetic resonance imaging, and the coregistered images obtained in 17 patients with suspected high-grade gliomas. The accumulation of 18F-FCho in the normal structures and in brain lesions was visually and semiquantitatively assessed. A 4-point grading system was used for the visual analysis. A standardized uptake value (SUV) was used to quantify uptake. RESULTS: In the normal brain parenchyma, 18F-FCho uptake was faint (SUVmean, 0.15 ± 0.03 (SD)). Uptake was generally moderate in the choroid plexus (SUVmean, 0.82 ± 0.16), cavernous sinus (SUVmean, 0.87 ± 0.19), extraocular eye muscles (SUVmean, 1.10 ± 0.27), masticatory muscles (SUVmean, 0.99 ± 0.22), and bone marrow (SUVmean, 1.06 ± 0.26), whereas uptake was usually moderately intense in the pituitary gland (SUVmean, 1.90 ± 0.21). Uptake was variable in the lacrimal glands and the mucosa of the nasal cavity (for SUVmean of subgroups see text). Intense uptake was observed in the parotid glands (SUVmean, 3.27 ± 0.73). (Moderately) intense 18F-FCho uptake was observed in glioblastomas (range SUVmax, 2.26-6.37) and typical meningiomas (range SUVmax, 3.75-5.81). Uptake was globally faint in grade II and III gliomas (range SUVmax, 0.33-0.78). 18F-FCho uptake was also demonstrated in benign lesions, such as a tumefactive demyelinating brain lesion. CONCLUSIONS: 18F-FCho uptake was faint in the normal brain parenchyma and usually moderate in the choroid plexus, cavernous sinus, extraocular eye muscles, masticatory muscles, and bone marrow. Uptake in the pituitary gland was generally moderately intense, whereas uptake in the lacrimal glands and the mucosa of the nasal cavity was variable. Parotid glands had intense uptake. Also, uptake in glioblastomas and meningiomas was usually (moderately) intense, whereas uptake in grade II and III gliomas was globally faint. However, 18F-FCho uptake was not tumor specific.